A newborn can feel surprisingly warm one minute and have cool hands the next, which is why touch alone can be confusing. Young babies are still developing their ability to regulate body temperature, so the safest approach is to look at the whole picture: how your baby seems, the room temperature, what they are wearing and, when you are concerned, an actual thermometer reading.
This guide explains how to check a newborn temperature at home, what can affect the result, how to reduce the risk of newborn overheating and when an unusual reading needs prompt medical advice. It is practical guidance rather than a way to diagnose illness, because very young babies can become unwell quickly and sometimes show only subtle signs.
What is a normal newborn temperature?
The NHS says a normal temperature in babies and children is around 36.4°C, although it can vary slightly. A temperature of 38°C or higher is considered a fever.
For a baby under 3 months old, a reading of 38°C or above needs urgent medical advice. NHS guidance also warns that a temperature below 36°C can be a sign of serious illness in babies and young children. If you get a reading below 36°C, check it twice more within 10 minutes to make sure the result is genuine and seek prompt medical advice.
The number matters, but so does your baby’s behaviour. A newborn who is unusually sleepy, difficult to wake, feeding poorly, breathing differently, looking pale or mottled, or simply seems seriously unwell needs medical attention even if the thermometer does not show a fever.
How to check a baby’s temperature correctly
For babies and children under 5, the NHS recommends using a digital thermometer in the armpit. This is usually the simplest reliable method at home and avoids some of the placement problems that can affect ear thermometers in very small babies.
Using a digital baby thermometer
Place the thermometer high in your baby’s armpit, then gently hold the arm snugly against the side of the body. Keep it there for the time stated in the manufacturer’s instructions. Many digital thermometers beep when the reading is ready.
If your baby is wriggly, sit down first and hold them securely. Try not to measure immediately after they have been carried tightly wrapped, because warmth from clothing and close contact may temporarily affect the result.
Which thermometers are best avoided?
Forehead strip thermometers measure skin temperature rather than body temperature, so they are not a good choice when you need a dependable reading. Ear thermometers can be fast, but the NHS notes that they may give misleading results if they are not positioned correctly, which is particularly easy in babies because their ear canals are so small.
What can affect a newborn temperature reading?
A baby’s temperature can be slightly altered if they have been wrapped tightly in a blanket, been in a very warm room, worn lots of clothes or recently had a bath. If one of these applies, remove obvious excess layers and allow your baby to settle for a few minutes without letting them become cold or shivery. Then check the temperature again.
For example, a baby may come indoors wearing a vest, sleepsuit, pramsuit and hat, then remain bundled up in a heated room. Their chest may feel hot and they may become sweaty. Take off the outdoor layers and hat, let them settle comfortably, and reassess rather than assuming the warmth automatically means fever.
How to avoid newborn overheating
Overheating is not just uncomfortable. Safer-sleep guidance warns that getting too hot is associated with a higher risk of sudden infant death syndrome. For sleep, NHS and Lullaby Trust guidance recommends a room temperature of about 16°C to 20°C.
Use a room thermometer rather than guessing, especially in centrally heated homes or during hot weather. Dress your baby for the room rather than the season outside, and remove hats and extra outdoor clothing once you come indoors. Avoid placing the cot or Moses basket next to a radiator, heater, fire or in direct sunlight.
Check the chest or back of the neck, not the hands
Cool hands or feet can be normal. To judge comfort, feel the chest, tummy or back of the neck instead. If the skin feels hot or sweaty, remove a layer of clothing or bedding. Lightweight bedding or a well-fitting baby sleep bag is easier to adjust than thick, padded layers, and your baby’s head should remain uncovered during sleep.
When an unusual temperature needs medical advice
With newborns, it is safer to act early than to watch a worrying reading for hours. If your baby is under 3 months and has a temperature of 38°C or higher, contact an urgent GP service or NHS 111 promptly. If a very young baby has a temperature below 36°C, repeat the measurement to confirm it and seek medical advice.
Call 999 or go to A&E if your baby appears seriously unwell, has difficulty breathing, is very hard to wake, has a seizure, develops blue or grey colouring, or has a rash that does not fade under pressure. Trust your judgement too: a marked change from your baby’s usual behaviour can matter even without a high temperature.
Related topics worth reading next include newborn sleep safety, how to dress a newborn for sleep and signs a newborn may be unwell.
Frequently asked questions
What temperature is too high for a newborn?
For a baby under 3 months old, 38°C or higher needs urgent medical advice. Use a digital thermometer in the armpit rather than relying on how warm the forehead feels.
What temperature is too low for a newborn?
A reading below 36°C can be a warning sign. Check the temperature twice more within 10 minutes to confirm it and seek prompt medical advice, particularly if your baby seems sleepy, cold, pale or unwell.
Can I check my baby’s temperature by touch?
Touch can alert you that something may be different, but it cannot tell you the actual temperature. If your baby’s chest or back feels unusually hot, or they seem unwell, use a digital thermometer.
How can I tell if my newborn is overheating while asleep?
Feel the chest, tummy or back of the neck. Hot or sweaty skin suggests your baby may be too warm. Remove a layer, check the room temperature and keep the sleep space away from direct heat sources.
Keeping temperature checks simple
Keep a digital thermometer at home, know how to use it in the armpit, aim for a comfortable sleep environment and pay attention to changes in your baby’s usual behaviour. Most importantly, treat unusual readings in very young babies seriously. If a newborn has a fever, a confirmed low temperature or looks unwell, prompt professional advice is the safest next step.